Grammar: ¿Pretérito imperfecto o pretérito indefinido?

This verb tense also has several uses. One example is the description of repetitive actions or habits in the past.

– Cuando tenía 20 años ella jugaba al fútbol todos los fines de semana. When she was 20, she played football every weekend.

– Yo trabajaba todos los lunes de mañana. I used to work every Monday morning.

Describing context and setting: To establish the context and describe past situations, such as the weather, the time, mood, physical appearance, and other details, the imperfect tense is generally the right choice.

– Ayer hacía mucho frío. Yesterday, it was very cold.
– ¿Qué hora era cuando llegaste? What time was it when you arrived? It was 4 o’clock.

– Eran las 4. It was 4 o’clock.

– Ella estaba contenta porque había aprobado el examen. She was happy because she had passed the exam.

– Yo, cuando era adolescente, era muy delgado. When I was a teenager, I was very thin.

It’s also usually the correct choice when we want to describe simultaneous actions.

Yo desayunaba mientras ella leía. I was having breakfast while she was reading.
Él cantaba y todos lo aplaudían. He was singing, and everyone was clapping for him.

To describe someone’s age and other characteristics of people or things in the past, we generally also use the imperfecto.

Cuando yo tenía 20 años ya sabía tocar la guitarra. When I was 20, I already knew how to play the guitar.
La casa era muy vieja, se estaba cayendo a pedazos. The house was very old, it was falling apart.

As you may have noticed, when we use this verb tense, the end of the action is unknown, irrelevant, or the action may not have ended. Let’s look at some examples comparing sentences with similar ones in the indefinido.

Cuando yo tenía 20 años ya sabía tocar la guitarra. When I was 20, I already knew how to play the guitar. > I probably still know how to play, the end of the action is irrelevant.
Cuando yo tenía 20 años toqué la guitarra por primera vez en un concierto. When I was 20, I played the guitar for the first time at a concert. >The concert is already over.
Cuando yo tenía 20 años, tocaba la guitarra en conciertos. When I was 20 years old, I used to play the guitar in concerts. >Repetitive action, we don’t know if I keep doing it or not.

Mientras yo cocinaba, ella limpiaba. While I was cooking, she was cleaning. >The two actions occur simultaneously.
Yo cociné y ella limpió. I cooked, and she cleaned. >Both actions ended, but we don’t know if they happened at the same time or which one happened first.

Él tenía 20 años en 1997. He was 20 in 1997. >Describing a characteristic: his age.
Te entiendo, yo también tuve 20 años. I understand, I was 20 years old once too. >I’m no longer 20, and it’s semantically important to highlight this.

¿Qué comías en Alemania? What did you eat in Germany? >Asking about the person’s eating habits in Germany. The most likely answer is a description of their dietary habits during that time. It could refer to someone who lived in Germany or someone who visited the country.
¿Qué comiste en Alemania? What did you eat in Germany? >Asking about specific dishes the person tried in that country. The most likely answer is a list of particular dishes, probably those that might catch the listener’s attention for being different from what they’re used to. It refers to someone who visited the country, not to someone who lived there, as this person would have had eating habits.

One last use of the imperfect we’ll cover in this article is for politeness. In Spanish, politeness formulas are not as common in spoken language as they are in other languages, but this one is frequently used. In this case, the imperfect tense is used in relation to the speaker’s intentions, and it’s generally used with the verb querer (to want).

(Yo) Quiero saber el precio de esta camisa. I want to know the price of this shirt. >Direct.
(Yo) Quería saber el precio de esta camisa. I wanted to know the price of this shirt. >Polite.

¡Hola! Quiero hacerte una pregunta. Hi! I want to ask you a question. > Direct.
¡Hola! Quería hacerte una pregunta. Hi! I wanted to ask you a question. > Polite.

In the case where we’re describing an action interrupted by another, for the first one we’ll use the imperfecto, and for the second, the indefinido.

Estábamos cenando cuando sonó el timbre. We were having dinner when the doorbell rang.
Ella estaba dormida cuando él llegó. She was asleep when he arrived.
Ella miraba la televisión cuando comenzó la tormenta. She was watching TV when the storm started.